1. Field of the Invention
The present invention relates generally to adhesive paper products such as labels, tape and the like. More particularly, the invention is directed to adhesively backed paper that is soluble or otherwise degradable in water or other liquids.
2. Description of Prior Art
By way of background, water soluble paper laminates for use as adhesive tape and labels have been constructed with a layer of water soluble paper backed by a layer of water soluble, pressure-sensitive adhesive having a peelable release liner (adhesive backing). This prior art construction is shown in FIG. 1. During use, the release liner is peeled off and the adhesive side of the tape or label is adhered to a surface. A disadvantage of the construction of FIG. 1 is that the adhesive properties may be degraded if the material is stored too long (e.g., more than a few months) or is stored improperly (e.g., exposed to extreme temperature or humidity, direct sunlight, etc.).
In an attempt to address the foregoing problem, a barrier coating made from unknown material has been applied between the paper and the adhesive backing. This modified construction is shown in FIG. 2. The solution of FIG. 2 has been shown to provide a shelf life of approximately 3-6 months.
It is to improvements in the above-described field that the present invention is directed. What is needed is a solution that further extends the shelf life of a degradable adhesively-backed paper product beyond what is presently achievable.